I just wanted to add more color around SamOh’s comment above, which may cause a big concern.
An August 2003 USCIS memo provides that one may still be eligible to use AC21 even even if an approved I-140 petition is revoked after the I-485 has been pending 180 days or more.
Under Section 106 of the American Competitiveness in the Twenty-First Century Act (AC21) of 2000, now incorporated into section 204(j) of the Immigration and Naturalization Act (INA), an adjustment application remains valid with respect to a new job if the adjustment application has been filed and remained unadjudicated for 180 days or more. The new job must be in the same or a similar occupational classification as the job for which the application was filed.
In conclusion, as long as you changed a job in the same or a similar occupational classification after your I-485 has been pending 180 days or more, you should be fine.
Yes, it would be a safe bet that you submit evidence to USCIS that the new job is in the same or a similar occupational classification, since the memo indicates that it is expected that the alien will have submitted such evidence.
If the underlying approved I-140 is revoked or withdrawn, and the alien has not submitted such evidence, the adjudicating officer must issue a NOID (Notice of Intent to Deny) the pending I-485 (NOT immediately deny the I-485). If the evidence of a new qualifying employment submitted in response of the NOID is timely filed, the officer may consider the approved I-140 to remain valid with respect to the new employment and may continue regular processing of the I-485.